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1 Introduction Anongoingchallengeintheopticalcommunicationsistomaximisethedatatransmissioncapacityofasinglefiber.TheintroductionofmultiplechannelsthroughDenseWavelengthDivisionMultiplexing(DWDM )systemshasgreatlyimprovedthiscapacity ,becauseofthesteady… 相似文献
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一种新型结构的单模光纤1×4分束器 总被引:2,自引:0,他引:2
以线性耦合波方程为基础,分析了具有平面型结构的五光纤耦合系统的功率耦合特性,提出了研制新型结构的单模光纤1×4分束器的方法,并经实验验证。所研制的1×4分束器的性能和外形尺寸与常规的2×2单模光纤耦合器相比,都较为接近。 相似文献
75.
强磁场中Rb D2线法拉第反常色散滤光器特性研究 总被引:3,自引:2,他引:1
报道强磁场中RbD_2线反常色散光学滤波器的理论模型与实验研究,讨论了强磁场中RbD-2线法拉第反常色散秀射谱及其磁场,温度调谐特性. 相似文献
76.
一类边值问题的随机分析解法 总被引:2,自引:0,他引:2
本文首先利用一类偏微分方程边值问题基本解的性质,构造并讨论了R~d中有界C~3区域上反射扩散过程及相应的边界局部时.作为它们的应用,我们用随机分析的方法给出了一类偏微分方程第三边值问题唯一有界解的明显表达式. 相似文献
77.
The combination of scanning electrochemical microscopy (SECM) with piezoelectric quartz crystal impedance (PQCI) analysis was proposed as a novel multiparameter method for investigating the cyclic voltammetric growth of poly(o-phenylenediamine) (PoPD) thin films at Au electrodes in aqueous solutions of various pH values and the potentiostatic microetching (localized degradation) of these films in 0.10 mol/L aqueous H2SO4 for comparative examinations on polymer porosity and stability. Two potential-sweep ranges, -0.4 to 0.9 (I) and 0 to 0.9 (II) V versus SCE, and four solutions, acidic (A, 0.20 mol/L H2SO4 + 0.10 mol/L Na2SO4; B, 0.10 mol/L H2SO4 + 0.20 mol/L Na2SO4), neutral (C, 0.10 mol/L PBS + 0.20 mol/L Na2SO4, pH 7.2), and alkaline (D, 0.20 mol/L NaOH + 0.20 mol/L Na2SO4) aqueous solutions, were selected for PoPD growth. The pH increase for the polymerization solution increased the molar percentage of polyaniline-like chains in PoPD, as quantified from the current peaks at approximately 0.6 V versus a saturated calomel electrode (SCE) for the oxidation of -NH2 groups in as-prepared PoPD (grown from solutions C and D) during their redox switching in 0.10 mol/L aqueous H2SO4 for the first time. The unusual PQCI responses observed at negative potentials (potential range I) in the first several potential cycles during the cyclic voltammetric growth of PoPD in acidic and neutral solutions have been reasonably explained as being due to the precipitation/dissolution of the poorly soluble phenazinehydrine charge-transfer complexes developed during redox switching of oligomers for the first time, which brought about much less compact PoPD films and their higher degradability than those grown in the same solution but over potential range II. SECM, scanning electron microscopy (SEM), and piezoelectric quartz crystal (PQC) frequency were used to estimate the sizes of etched microscale spots. In addition, the x-, y-, or z-axis movement of a Pt microelectrode of 25-mum diameter near the PQC electrode was found to influence negligibly the PQCI responses in 1.0 mol/L aqueous Na2SO4 containing K4Fe(CN)6 up to 0.10 mol/L, and a new protocol of dynamically electrodepositing silver microwires via the chemical-lens method was proposed for examining the local mass-sensitivity distribution on the PQC surface. 相似文献
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A novel nanocomposite of quinone‐amine polymer and multiwalled carbon nanotubes was synthesized from iodate‐oxidation/Michael addition reaction of 1,2‐dihydroxybenzene with o‐phenylenediamine, which was characterized by TEM, FTIR and UV‐vis spectra. The nanocomposite modified Au electrode with well‐defined quinone redox peaks effectively mediated the oxidation of NADH in pH 7.0 phosphate buffer, with an overpotential decrease by ca. 470 mV (vs. bare Au), a limit of detection of 6.4 nmol L?1 and good antiinterferent ability. 相似文献
79.
Through admittance measurements of two piezoelectric quartz crystals in parallel on one impedance analyzer and then non-linear fitting according to an equivalent circuit of two parallel Butterworth-Van Dyke circuits, we have simultaneously obtained accurate and precise impedance responses of two one-face sealed crystals to changes in solution density and viscosity, temperature, conductance, and/or electrode mass. A series of sucrose aqueous solutions, ferri-/ferrocyanide redox switching, hot water cooling, a series of NaClO4 aqueous solutions, bovine serum albumin adsorption and silver electrodeposition/stripping were selected as model systems for such purposes. Galvanostatic charging/discharging reactions at positive and negative poles in a Ni-Zn battery were synchronously monitored, with some quartz crystal microbalance (QCM) insights into the second reduction process of nickel hydroxide film. In all cases, the crystal immersion angle effect was found to be negligible. The present method as a versatile one is highly recommended for informative two-electrode monitoring of two concurrent chemical or biological events, or for check and/or compensation of effects due to solution density, viscosity, temperature and/or conductance during QCM researches. 相似文献
80.
Xueqin Jiang Zhijun Cao Hao Tang Liang Tan Qingji Xie Shouzhuo Yao 《Electrochemistry communications》2008,10(9):1235-1237
The electrochemical surface plasmon resonance (ESPR) technique was used to investigate the electrodeposition of the charge-transfer complex (CTC) generated during electrooxidation of o-tolidine (o-TD) in pH 4.5 Britton–Robinson buffers and the effects of coexisting dermatan sulfate (DS). The peak-type surface plasmon resonance (SPR) responses (versus time) observed in the cyclic voltammetric experiments indicated the precipitation and dissolution of a poorly soluble CTC, an oxidation intermediate, formed during the redox switching of o-TD in a weakly acidic medium. The effects of potential scan rate and solution pH were examined. The height of the peak-type SPR response to the redox switching of the o-TD/CTC “couple” was notably enhanced by the introduction of DS, due to the formation of a mass-enhanced CTC-DS adduct, as also supported by UV–vis spectroelectrochemistry. The SPR signal responded linearly to the DS concentration up to 14 μmol L−1, with a limit of detection (LOD) down to 8 nmol L−1 (S/N = 3). The analytical performance of the ESPR technique was found to be better than that of the quartz crystal microbalance technique with an LOD value of 70 nmol L−1. The CTC-based ESPR assay is recommended as a new, highly sensitive and dynamically surface-regenerated biosensing technology for other species. 相似文献